1. Field of the Invention
The present invention relates generally to a mobile phone case with an embedded wireless interface for enabling communications between a continuous glucose monitoring (CGM) sensor and a mobile phone. More specifically, the present invention provides a mobile phone case including autonomous battery power and an autonomous alarm speaker for enabling communication with a CGM sensor in situations where a mobile phone is unavailable.
2. Description of the Related Art
Diabetes is a group of diseases marked by high levels of blood glucose resulting from defects in insulin production, insulin action, or both. Diabetes can lead to serious complications and premature death, but there are well-known products available for patients with diabetes to help control the disease and lower the risk of complications.
Treatment options for diabetics include specialized diets, oral medications and/or insulin therapy. The primary goal for diabetes treatment is to control a diabetic's blood glucose (sugar) level in order to increase the chances of a complication-free life. Because of the nature of diabetes and its short-term and long-term complications, it is important that diabetics have a constant awareness of the level of glucose in their blood.
There are typically two methods for measuring a user's blood glucose level. One method uses an electronic blood glucose meter. A sample of blood is obtained by piercing the skin of a user with a lancet. The sample of blood is then placed on a chemically-active test-strip, which interfaces with the blood glucose meter. Within several seconds of inserting the test-strip into the blood glucose meter, the blood glucose level of the user is read and shown on the digital display of the blood glucose meter.
The blood glucose meter method provides an accurate snapshot of a user's blood glucose level at a single moment in time. However, the blood glucose meter method does not indicate whether the user's glucose level is rising, falling, or steady. Additionally, the blood glucose meter method fails to capture a user's changing blood sugar levels after meals, between meals, and during the night.
An alternative method for measuring a user's blood glucose level in a continuous or real-time basis is to use a continuous glucose monitor (CGM) system. A CGM system generally includes a sensor, a transmitter, and a handheld receiver.
A typical glucose oxidase sensor is a small, thin metallic filament that is inserted just below the skin using a mechanical insertion device. The glucose oxidase sensor rests in the fatty layer below the skin, so it is generally not felt by the user wearing it. An adhesive patch or tape covering keeps the sensor securely in place. The glucose oxidase sensor contains a chemical that reacts with the glucose in the interstitial fluid, that is, fluid between the fat cells below the skin surface, causing a small electric current. Of course, embodiments of the present invention may be used with any type of sensor including a wide variety of known glucose sensors.
After the glucose oxidase sensor is inserted, a radio transmitter receives the tiny electric current from the glucose oxidase sensor and sends out a short-range radio signal. The signal from the transmitter is received by a battery-powered handheld device that displays the glucose measurement. Preferably, the receiver analyzes and displays historical data including but not limited to trend graphs, up/down arrows, and various statistics.
The handheld receiver can be customized to alert the user of glucose values that exceed certain high or low levels. This is important to those with hypoglycemia who could otherwise be unaware to potentially dangerous low blood glucose. Likewise, the high alert allows the user to act in a timely manner in order to avoid prolonged bouts of hyperglycemia and extreme high values. The alerts enable more aggressive management of after-meal blood glucose levels, and serve as an effective early warning system to prevent ketoacidosis. Certain receiver devices also provide predictive alerts based on the present glucose value and the current rate of change.
Because of the ubiquity of mobile phones, there is considerable interest in integrating mobile phones as a replacement to the handheld receivers in a CGM system. Replacing a handheld receiver with a mobile phone would provide greater convenience to a user by reducing the amount of devices that the user would have to carry on their person. Moreover, a mobile phone would provide a convenient touchscreen interface, and enable a user to easily update the software.
There are, however, several issues that could potentially arise from using a mobile phone as a replacement to a CGM system receiver. First, due to the high usage of mobile phones, their batteries must be charged frequently, thus presenting a high probability that the batteries could die and the mobile phone be unavailable to communicate with a CGM sensor at some point. Second, unlike a CGM system handheld receiver, the mobile phone may be loaded with additional software including some that could cause the mobile phone to malfunction either by accident or possibly even a virus. Finally, the wireless interfaces currently available on mobile phones tend to be high power/high data rate interfaces such as Bluetooth, and therefore, not ideally suited for use with a CGM system sensor where battery-life and battery-size are important factors.
Accordingly, there is a need for a mobile phone case including a wireless interface for enabling communications between a CGM sensor and a mobile phone. Additionally, there is a need for a mobile phone case that provides autonomous battery power, autonomous communication with the GGM sensor, and an autonomous alarm speaker, for enabling communication with a CGM sensor in situations where the mobile phone battery is dead, the mobile phone is not functioning, or is otherwise unavailable.
Moreover, there is a need for a mobile phone case including a pass-through connector for simultaneously recharging an autonomous battery embedded in the mobile phone case while the mobile phone is being charged, which also provides a wired interface for communicating with the mobile phone.